Polyether ester elastomer comprising polytrimethylene ether ester soft segment and trimethylene ester hard segment

ABSTRACT

A polyether ester elastomer comprising about 90—about 60 weight % polytrimethylene ether ester soft segment and about 10—about 40 weight % trimethylene ester hard segment, and use thereof in fibers and other shaped articles. The fibers have excellent physical properties, including superior strength and stretch recovery.

FIELD OF THE INVENTION

[0001] The present invention relates to polyether ester elastomers, andmanufacture and use thereof.

TECHNICAL BACKGROUND

[0002] Thermoplastic elastomers (TPEs) are a class of polymers whichcombine the properties of two other classes of polymers, namelythermoplastics, which may be reformed upon heating, and elastomers whichare rubber-like polymers. One form of TPE is a block copolymer, usuallycontaining some blocks whose polymer properties usually resemble thoseof thermoplastics, and some blocks whose properties usually resemblethose of elastomers. Those blocks whose properties resemblethermoplastics are often referred to as “hard” segments, while thoseblocks whose properties resemble elastomers are often referred to as“soft” segments. It is believed that the hard segments provide similarproperties as chemical crosslinks in traditional thermosettingelastomers, while the soft segments provide rubber-like properties.

[0003] The weight and mole ratios of hard to soft segments, as well asthe type of the segments determines to a great extent the properties ofthe resulting TPE. For example, longer soft segments usually lead toTPEs having lower initial tensile modulus, while a high percent of hardsegments leads to polymers with higher initial tensile modulus. Otherproperties may be affected as well. Thus, manipulation on the molecularlevel affects changes in the properties of TPEs, and improved TPEs areconstantly being sought.

[0004] Frequently the soft segments of TPEs are formed frompoly(alkylene oxide) segments. Heretofore the principle polyetherpolyols have been based on polymers derived from cyclic ethers such asethylene oxide, 1,2-propylene oxide and tetrahydrofuran. These cyclicethers are readily available from commercial sources, and when subjectedto ring opening polymerization, provide the polyether glycol, e.g.,polyethylene ether glycol (PEG), poly(1,2-propylene) glycol (PPG), andpolytetramethylene ether glycol (PO4G, also referred to as PTMEG),respectively.

[0005] U.S. Pat. No. 3,023,192 Shivers discloses segmentedcopolyetheresters and elastic polymer yams made from them. The segmentedcopolyetheresters are prepared from (a) dicarboxylic acids orester-forming derivatives, (b) polyethers of the formula HO(RO)_(n)H,and (c) dihydroxy compounds selected from bis-phenols and loweraliphatic glycols. R is a divalent radical, and representativepolyethers include polyethylene ether glycol, polypropylene glycol,polytetramethylene glycol, polyhexamethylene glycol, and so on, and n isan integer of a value to provide a polyether with a molecular weight ofabout 350-6,000.

[0006] U.S. Pat. No. 3,651,014 Witsiepe discloses copolyetherestersconsisting of recurring long chain and short chain ester units. The longchain ester units are represented by the formula:

[0007] The short chain ester units are represented by the formula:

[0008] R and R′ are divalent radicals remaining after removal ofcarboxyl groups from a dicarboxylic acid having a molecular weight ofless than 300. G is a divalent radical remaining after removal ofterminal hydroxyl groups from a long chain polymeric ether glycol,having a molecular weight greater than 600 and a melting point below 55°C. D is a divalent radical remaining after removal of terminal hydroxylgroups from a low molecular weight diol. The copolyesters of this patentare prepared from dicarboxylic acids (or their equivalents), (b) linearlong chain glycols and (c) low molecular weight diols; provided however,that there must be used either at least two dicarboxylic acids (or theirequivalents) or at least two low molecular weight diols. A list of longchain glycols including “poly(1,2 and 1,3-propylene oxide) glycol” ispresent at column 4; however, the examples are directed to the use ofPO4G as the long chain polymeric ether glycol.

[0009] U.S. Pat. No. 4,906,729 Greene et al. discloses segmentedthermoplastic copolyetheresters having soft segments formed from a longchain polyalkyleneether glycol containing 80 to 97 mole percent ofcopolymerized tetrahydrofuran and 3 to 20 mole percent of acopolymerized cyclic alkylene oxide, preferably copolymerized3-methyltetrahydrofuran, and fibers and films with an improvedcombination of tenacity, unload power, melting temperatures and set.

[0010] U.S. Pat. No. 4,937,314 Greene discloses thermoplasticcopolyetherester elastomers comprising at least 70 weight % softsegments derived from poly(alkylene oxide) glycols and terephthalicacid. The hard segments constitute 10-30 weight % of the elastomer andare 95-100% poly(1,3-propylene terephthalate). The specificationdiscloses that the poly(alkylene oxide) glycols have a molecular weightof about 1,500—about 5,000 and a carbon-to-oxygen ratio of 2-4.3.Representative poly(alkylene oxide) glycols include poly(ethylene oxide)glycol, poly(1,2-propylene oxide) glycol, poly(1,3-propylene oxide)glycol, poly(tetramethylene oxide) glycol (PO4G), etc. In the examples,the soft segments are based on PO4G and tetrahydrofuran/ethylene oxidecopolyethers.

[0011] U.S. Pat. No. 5,128,185 Greene describes thermoplasticcopolyetherester elastomers comprising at least 83 weight % softsegments derived from poly(alkylene oxide) glycols and terephthalicacid. The hard segments constitute 10-17 weight % of the elastomer andcomprises poly(1,3-propylenebibenzoate). The specification disclosesthat the poly(alkylene oxide) glycols having a molecular weight of about1,500—about 5,000 and a carbon-to-oxygen ratio of 2.5-4.3.Representative examples include poly(ethylene oxide) glycol,poly(1,2-propylene oxide) glycol, poly(1,3-propylene oxide) glycol,poly(tetramethylene oxide) glycol (PO4G), etc. In the examples, the softsegments are based on PO4G and tetrahydrofuran/3-methyl tetrahydrofuran.

[0012] JP 2000-256919 discloses a thermo-adhesive polyester conjugatefiber containing a polyether ester-type block copolymer having a hardsegment consisting of a polytrimethylene terephthalate polyester and asoft segment component consisting of a poly(alkylene oxide) glycolhaving an average molecular weight of 400-5,000. Poly(1,2-propyleneoxide) glycol, poly(ethylene oxide) glycol, and poly(tetramethyleneoxide) glycol are among the disclosed soft segments, and the later ispreferred. The conjugate fiber also contains a polytrimethyleneterephthalate polyester section.

[0013] All of the aforementioned documents are incorporated herein byreference.

[0014] TPEs based on those exemplified in the prior art are primarilybased on PO4G, copolymers of tetrahydrofuran and 3-alkyltetrahydrofuran,PEG, PPG and copolymers of these. While a range of polyether ester TPEscan be produced based on these polyethers, there remains the need for anoverall improvement in physical properties, including tensile strength,elongation, and stretch-recovery properties, including tensile set andrecovery power. The present invention provides distinct advantagestoward achieving an overall improved balance of these properties.Particularly unexpected are a large increase in recovery power and alarge decrease in stress decay.

SUMMARY OF THE INVENTION

[0015] The invention is directed to a polyether ester elastomercomprising about 90—about 60 weight % polytrimethylene ether ester softsegment and about 10—about 40 weight % trimethylene ester hard segment.They preferably contain at least about 70 weight %, more preferably atleast about 74 weight %, polytrimethylene ether ester soft segment, andpreferably contain up to about 85, more preferably up to about 82 weight%, polytrimethylene ether ester soft segment. They preferably contain atleast about 15 weight %, more preferably at least about 18 weight %, andpreferably contain up to about 30 weight %, more preferably up to about26 weight %, trimethylene ester hard segment.

[0016] The mole ratio of hard segment to soft segment is preferably atleast about 2.0, more preferably at least about 2.5, and is preferablyup to about 4.5, more preferably up to about 4.0.

[0017] The polyether ester preferably has an inherent viscosity of atleast about 1.4 dl/g, more preferably at least about 1.6 dl/g, andpreferably up to about 2.4 dl/g, more preferably up to about 1.9 dl/g.

[0018] The polyether ester is preferably prepared by providing andreacting (a) polytrimethylene ether glycol, (b) 1,3-propanediol and (c)dicarboxylic acid, ester, acid chloride or acid anhydride.

[0019] In a preferred embodiment, at least 40 weight % of the polymericether glycol used to form the polytrimethylene ether ester soft segmentis the polytrimethylene ether glycol, and up to 60 weight % of thepolymeric ether glycol used to form the polytrimethylene ether estersoft segment is polymeric ether glycol preferably selected from thegroup consisting of polyethylene ether glycol, polypropylene etherglycol, polytetramethylene ether glycol, polyhexamethylene ether glycol,and copolymers of tetrahydrofuran and 3-alkyl tetrahydrofuran, andmixtures thereof.

[0020] In a preferred embodiment, at least 85 weight % of the polymericether glycol used to form the polytrimethylene ether ester soft segmentis the polytrimethylene ether glycol.

[0021] Preferably, the polytrimethylene ether glycol has number averagemolecular weight of at least about 1,000, more preferably at least about1,500. Preferably, the polytrimethylene ether glycol has number averagemolecular weight of less than about 5,000, more preferably up to about3,500.

[0022] In a preferred embodiment, at least 75 mole % of the diol used toform the trimethylene ester hard segment is 1,3-propanediol and up to 25mole % of the diol are diol other than 1,3-propanediol preferably with2-15 carbon atoms, more preferably selected from ethylene, isobutylene,butylene, pentamethylene, 2,2-dimethyltrimethylene,2-methyltrimethylene, hexamethylene and decamethylene glycols, dihydroxycyclohexane, cyclohexane dimethanol, hydroquinone bis(2-hydroxyethyl)ether, and mixtures thereof.

[0023] Preferred diol other than 1,3-propanediol contain 2-8 carbonatoms. Most preferred are ethylene glycol and 1,4-butanediol, andmixtures thereof.

[0024] In a preferred embodiment, at least 85 mole % of the diol used toform the trimethylene ester hard segment is 1,3-propanediol.

[0025] Preferably, the dicarboxylic acid, ester, acid chloride or acidanhydride is an aromatic dicarboxylic acid or ester, more preferablyselected from the group consisting of dimethyl terephthalate,bibenzoate, isophthlate, phthalate and naphthalate; terephthalic,bibenzoic, isophthalic, phthalic and naphthalic acid; and mixturesthereof. More preferred are the aromatic diesters.

[0026] In a preferred embodiment, at least 50 mole % (more preferably atleast 70 mole % and even more preferably at least 85 mole %) of thedicarboxylic acid, ester, acid chloride or acid anhydride is selectedfrom the group consisting of terephthalic acid and dimethylterephthalate.

[0027] In another preferred embodiment, the dicarboxylic acid, ester,acid chloride or acid anhydride are selected from the group consistingof terephthalic acid and dimethyl terephthalate.

[0028] In another embodiment, the invention is directed to the polyetherester being prepared by providing and reacting polytrimethylene etherglycol and polytetramethylene ester.

[0029] In one embodiment, the invention is directed to a polyether estercomprising a soft segment represented by the structure:

[0030] and a hard segment represented by the structure:

[0031] where x is about 17 to about 86 and R and R′, which may be thesame or different, are divalent radicals remaining after removal ofcarboxyl functionalities from a dicarboxylic acid equivalent.

[0032] The invention is also directed to fibers prepared from thepolyether ester.

[0033] Preferred fibers include monocomponent filament, staple fiber,multicomponent fiber such as bicomponent fiber (containing the polyetherester as at least one component). The fibers are used to prepare woven,knit and nonwoven fabric.

[0034] The invention is further directed to the processes of preparingthe polyether ester, fibers and fabrics.

[0035] The polyether esters of this invention can be used to preparemelt spinnable thermoplastic elastomers having excellent strength andstretch-recovery properties, not heretofore achieved.

DETAILED DESCRIPTION OF THE INVENTION

[0036] The invention is directed to a polyether ester elastomercomprising about 90—about 60 weight % polytrimethylene ether ester softsegment and about 10—about 40 weight % trimethylene ester hard segment.They preferably contain at least about 70 weight %, more preferably atleast about 74 weight %, polytrimethylene ether ester soft segment, andpreferably contain up to about 85, more preferably up to about 82 weight%, polytrimethylene ether ester soft segment. They preferably contain atleast about 15, more preferably at least about 18 weight %, andpreferably contain up to about 30 weight %, more preferably up to about26 weight %, trimethylene ester hard segment.

[0037] The polyether ester preferably has an inherent viscosity of atleast about 1.4 dl/g, more preferably at least about 1.6 dl/g, andpreferably up to about 2.4 dl/g, more preferably up to about 1.9 dl/g.

[0038] Herein, “polytrimethylene ether ester soft segment” and “softsegment” are used to refer to the reaction product of polymeric etherglycol and dicarboxylic acid equivalent which forms an ester connection,wherein at least 40 weight % of the polymeric ether glycol used to formthe soft segment is polytrimethylene ether glycol (PO3G). Preferably atleast 45 weight %, more preferably at least 50 weight %, even morepreferably at least 85 weight %, and most preferably about 95-100 weight%, of the polymeric ether glycol used to form the soft segment is PO3G.

[0039] When referring to the polytrimethylene ether glycol, dicarboxylicacid equivalent, etc., it should be understood that reference is to oneor more of these items. Thus, for instance, when referring to at least40 weight % of the polymeric ether glycol used to form the soft segmentbeing polytrimethylene ether glycol, it should be understood that one ormore polytrimethylene ether glycol can be used.

[0040] When PO3G is used to form the soft segment, it can be representedas comprising units represented by the following structure:

[0041] wherein R represents a divalent radical remaining after removalof carboxyl functionalities from a dicarboxylic acid equivalent.

[0042] A wide range of molecular weights of the PO3G can be used.Preferably the PO3G has a number average molecular weight (Mn) of atleast about 1,000, more preferably at least about 1,500, and mostpreferably at least about 2,000. The Mn is preferably less than about5000, more preferably less than about 4,000, and most preferably lessthan about 3,500. Therefore, x in the above formula is at least about17, more preferably at least about 25 and most preferably at least about34, and is less than about 86, more preferably less than about 67 andmost preferably less than about 60. PO3G's useful for this invention aredescribed in U.S. patent application Ser. Nos. 09/738,688 and09/738,689, both filed Dec. 15, 2000, and their PCT counterparts WO01/44348 and 01/44150, all of which are incorporated herein byreference.

[0043] PO3G can be prepared by any process known in the art. Forexample, PO3G can be prepared by dehydration of 1,3-propanediol or byring opening polymerization of oxetane. The process is irrelevant solong as the polyether glycol meets the specifications for the finalpolymer product. Methods for making PO3G are described in U.S. patentapplication Ser. Nos. 09/738,688 and 09/738,689, both filed Dec. 15,2000, and their PCT counterparts WO 01/44348 and 01/44150, all of whichare incorporated herein by reference.

[0044] Up to 60 weight % of the soft segment may comprise polymericether glycol other than PO3G. Preferred are those selected from thegroup consisting of polyethylene ether glycol (PEG), polypropylene etherglycol (PPG), polytetramethylene ether glycol (PO4G), polyhexamethyleneether glycol, and copolymers of tetrahydrofuran and 3-alkyltetrahydrofuran (THF/3MeTHF). The other polymeric ether glycolspreferably have a number average molecular weight of at least about1,000, more preferably at least about 1,500, and preferably up to about5,000, more preferably up to about 3,500. An especially importantcopolymer is the copolymer of tetrahydrofuran and 3-methyltetrahydrofuran (THF/3MeTHF). Preferably up to 55 weight %, morepreferably up to 50 weight %, and most preferably up to 15 weight %, ofthe polyethylene ether glycol used to form the soft segment is PO3G.

[0045] By “trimethylene ester hard segment” and “hard segment” referenceis to the reaction product of diol(s) and dicarboxylic acid equivalentwhich forms an ester connection, wherein greater than 50 mole %, morepreferably at least 75 mole %, even more preferably at least 85 mole %and most preferably 95-100 mole %, of the diol used to form the hardsegment is 1,3-propanediol.

[0046] When 1,3-propanediol is used to form the hard segment, the hardsegment can be represented as comprising units having the followingstructure:

[0047] R′ represents a divalent radical remaining after removal ofcarboxyl functionalities from a dicarboxylic acid equivalent. In mostcases, the dicarboxylic acid equivalents used to prepare the softsegment and the hard segment of the polyether ester of this inventionwill be the same.

[0048] The hard segment can also be prepared with less than 50 mole %(preferably up to 25 mole %, more preferably up to 15 mole %), of diolsother than butylene diol. They preferably have a molecular weight lowerthan 400 g/mol. The other diols are preferably aliphatic diols and canbe acyclic or cyclic. Preferred are diols with 2-15 carbon atoms such asethylene, isobutylene, butylene, pentamethylene,2,2-dimethyltrimethylene, 2-methyltrimethylene, hexamethylene anddecamethylene glycols, dihydroxy cyclohexane, cyclohexane dimethanol,hydroquinone bis(2-hydroxyethyl) ether. Especially preferred arealiphatic diols containing 2-8 carbon atoms. Most preferred are diolsselected from the group consisting of ethylene glycol and1,4-butanediol. Two or more other diols can be used.

[0049] By “dicarboxylic acid equivalent” is meant dicarboxylic acids andtheir equivalents from the standpoint of making the compounds of thisinvention, as well as mixtures thereof. The equivalents are compoundswhich perform substantially like dicarboxylic acids in reaction withglycols and diols.

[0050] The dicarboxylic acid equivalents can be aromatic, aliphatic orcycloaliphatic. In this regard, “aromatic dicarboxylic acid equivalents”are dicarboxylic acid equivalents in which each carboxyl group isattached to a carbon atom in a benzene ring system such as thosementioned below. “Aliphatic dicarboxylic acid equivalents” aredicarboxylic acid equivalents in which each carboxyl group is attachedto a fully saturated carbon atom or to a carbon atom which is part of anolefinic double bond. If the carbon atom is in a ring, the equivalent is“cycloaliphatic.”

[0051] The dicarboxylic acid equivalent can contain any substituentgroups or combinations thereof, so long as the substituent groups do notinterfere with the polymerization reaction or adversely affect theproperties of the polyether ester product. Dicarboxylic acid equivalentsinclude dicarboxylic acids, diesters of dicarboxylic acids, anddiester-forming derivatives such as acid halides (e.g., acid chlorides)and anhydrides.

[0052] Especially preferred are the dicarboxylic acid equivalentsselected from the group consisting of dicarboxylic acids and diesters ofdicarboxylic acids. More preferred are dimethyl esters of dicarboxylicacids.

[0053] Preferred are the aromatic dicarboxylic acids or diesters bythemselves, or with small amounts of aliphatic or cycloaliphaticdicarboxylic acids or diesters. Most preferred are the dimethyl estersof aromatic dicarboxylic acids.

[0054] Representative aromatic dicarboxylic acids useful in the presentinvention include terephthalic acid, isophthalic acid, bibenzoic acid,naphthalic acid, substituted dicarboxylic compounds with benzene nucleisuch as bis(p-carboxyphenyl)methane, 1,5-naphthalene dicarboxylic acid,2,6-naphthalene dicarboxylic acid, 2,7-naphthalene dicarboxylic acid,4,4′-sulfonyl dibenzoic acid, etc., and C₁-C₁₀ alkyl and other ringsubstitution derivatives such as halo, alkoxy or aryl derivatives.Hydroxy acids such as p-(hydroxyethoxy)benzoic acid can also be usedproviding an aromatic dicarboxylic acid is also present. Representativealiphatic and cycloaliphatic dicarboxylic acids useful in this inventionare sebacic acid, 1,3-or 1,4-cyclohexane dicarboxylic acid, adipic acid,dodecanedioic acid, glutaric acid, succinic acid, oxalic acid, azelaicacid, diethylmalonic acid, fumaric acid, citraconic acid, allylmalonateacid, 4-cyclohexene-1,2-dicarboxylate acid, pimelic acid, suberic acid,2,5-diethyladipic acid, 2-5 2-ethylsuberic acid, 2,2,3,3-tetramethylsuccinic acid, cyclopentanenedicarboxylic acid, decahydro-1,5-(or2,6-)naphthalene dicarboxylic acid, 4,4′-bicyclohexyl dicarboxylic acid,4,4′methylenebis(cyclohexylcarboxylic acid), 3,4-furan dicarboxylate,and 1,1-cyclobutane dicarboxylate. The dicarboxylic acid equivalents inthe form of diesters, acid halides and anhydrides of the aforementionedaliphatic dicarboxylic acids are also useful to provide the polyetherester of the present invention. Representative aromatic diesters includedimethyl terephthalate, bibenzoate, isophthlate, phthalate andnaphthalate.

[0055] Of the above, preferred are terephthalic, bibenzoic, isophthalicand naphthalic acid; dimethyl terephthalate, bibenzoate, isophthlate,naphthalate and phthalate; and mixtures thereof. Particularly preferreddicarboxylic acid equivalents are the equivalents of phenylenedicarboxylic acids especially those selected from the group consistingof terephthalic and isophthalic acid and their diesters, especially thedimethyl esters, dimethyl terephthalate and dimethyl isophthalate. Inaddition, two or more dicarboxylic acids equivalents can be used. Forinstance, terephthalic acid or dimethyl terephthalate can be used withsmall amounts of the other dicarboxylic acid equivalents. In oneexample, a mixture of diesters of terephthalic acid and isophthalic acidwas used.

[0056] In a preferred embodiment, at least 50 mole % (more preferably atleast 70 mole %, even more preferably at least 85 mole % and mostpreferably about 95-100 mole %) of the dicarboxylic acid, ester, acidchloride or acid anhydride is selected from the group consisting ofterephthalic acid and dimethyl terephthalate.

[0057] The polyether ester is preferably prepared by providing andreacting (a) polytrimethylene ether glycol, (b) 1,3-propanediol and (c)dicarboxylic acid, ester, acid chloride or acid anhydride. The otherglycols, diols, etc., as described above are can also be provided andreacted.

[0058] The polyether ester of this invention is conveniently madestarting with a conventional ester exchange reaction, esterification ortransesterification depending on the starting dicarboxylic acidequivalent. For example, dimethyl terephthalate is heated withpolytrimethylene ether glycol and an excess of 1,3-propanediol in thepresence of a catalyst at 150-250° C., while distilling off the methanolformed by the ester exchange. This reaction is typically performed at apressure of about 1 atmosphere. The reaction product is a mixture of theester exchange reaction products of the dimethyl terephthalate and thepolytrimethylene ether glycol and 1,3-propanediol, primarilybis(hydroxybutyl) terephthalate with varying amounts of(hydroxy-polytrimethylene ether) terephthalates with a small amount ofthe corresponding oligomers. This mixture then undergoes polymerizationor polycondensation to a copolymer of an elastomeric polyether esterwith a polytrimethylene ether glycol soft segment and a trimethyleneterephthalate hard segment (condensation product of 1,3-propanediol anddimethyl terephthalate). The polymerization (polycondensation) involvesadditional ester exchange and distillation to remove the diol toincrease molecular weight. The polycondensation is typically performedunder vacuum. Pressure is typically in the range of 0.01 to 18 mm Hg(1.3 to 2400 Pa), preferably in the range of 0.05 to 4 mm Hg (6.7 to 553Pa) and most preferably 0.05 to 2 mm Hg. The polycondensation istypically run at a temperature in the range of about 220° C. to 260° C.

[0059] The ester exchange and polymerization steps may involvealternative processes than those described above. For example,polytrimethylene ether glycol can be reacted with polytrimethylene ester(e.g., polytrimethylene terephthalate) in the presence of catalyst (suchas those described for the ester exchange, preferably the titaniumcatalysts such as tetrabutyl titanate) until randomization occurs. Bothprocesses result in block copolymers.

[0060] To avoid excessive residence time at high temperatures andpossible accompanying thermal degradation, a catalyst can be employed inthe ester exchange. Catalysts useful in the ester exchange processinclude organic and inorganic compounds of titanium, lanthanum, tin,antimony, zirconium, and zinc. Titanium catalysts, such astetraisopropyl titanate and tetrabutyl titanate, are preferred and areadded in an amount of at least about 25 ppm (preferably at least about50 ppm and more preferably at least about 70 ppm) and up to about 1,000ppm (preferably up to about 700 ppm and more preferably up to about 400ppm) titanium by weight, based on the weight of the finished polymer.Tetraisopropyl titanate and tetrabutyl titanate are also effective aspolycondensation catalysts. Additional catalyst may be added after esterexchange or direct esterification reaction and prior to polymerization.Preferably the catalyst is tetrabutyl titanate (TBT).

[0061] Ester exchange polymerizations are generally conducted in themelt without added solvent, but inert solvents can be added tofacilitate removal of volatile components, such as water and diols atlow temperatures. This technique is useful during reaction of thepolytrimethylene ether glycol or the diol with the dicarboxylic acidequivalent, especially when it involves direct esterification, i.e., thedicarboxylic acid equivalent is a diacid. Other special polymerizationtechniques can be useful for preparation of specific polymers.Polymerization (polycondensation) can also be accomplished in the solidphase by heating divided solid product from the reaction ofpolytrimethylene ether glycol, a dicarboxylic acid equivalent, and1,3-propanediol in a vacuum or in a stream of inert gas to removeliberated diol. This type of polycondensation is referred to herein as“solid phase polymerization” (or abbreviated “SPP”).

[0062] Batch or continuous methods can be used for the processesdescribed above or for any stage of polyether ester preparation.Continuous polymerization, by ester exchange, is preferred.

[0063] In preparing the polyether ester elastomers of this invention, itis sometimes desirable to incorporate known branching agents to increasemelt strength. In such instances, a branching agent is typically used ina concentration of 0.00015 to 0.005 equivalents per 100 grams ofpolymer. The branching agent can be a polyol having 3-6 hydroxyl groups,a polycarboxylic acid having 3 or 4 carboxyl groups, or a hydroxy acidhaving a total of 3-6 hydroxyl and carboxyl groups. Representativepolyol branching agents include glycerol, sorbitol, pentaerytritol,1,1,4,4-tetrakis(hydroxymethyl)cyclohexane, trimethylol propane, and1,2,6-hexane triol. Suitable polycarboxylic acid branching agentsinclude hemimellitic, trimellitic, trimesic pyromellitic,1,1,2,2-ethanetetracarboxylic, 1,1,2-ethanetricarboxylic,1,3,5-pentanetricarboxylic, 1,2,3,4-cyclopentanetetracarboxylic and likeacids. Although the acids can be used as is, it is preferred to use themin the form of their lower alkyl esters.

[0064] Properties of the polyether ester will be influenced by varyingthe composition (dicarboxylic acid equivalent, 1,3-propanediol,polytrimethylene ether glycol, other diol, other glycol, etc.), theweight percent of hard segment, and the mole ratio of hard segment tosoft segment.

[0065] The preferred mole ratio of hard segment repeat units per softsegment (HS/SS) will depend on the composition of the hard segmentrepeat units, the weight percent hard segment, and the molecular weightof the polyether glycol. The mole ratio of hard segment to soft segmentis preferably at least about 2.0, more preferably at least about 2.5,and is preferably up to about 4.5, more preferably up to about 4.0. Whenthe ratio is below the minimum value of the range, the polymer maypossess an undesirably low tenacity and low melting temperature. Atratios higher than 5, difficulties may be encountered in melt processingthe polymer. The best balance of processability and properties areobtained with copolymers having a mole ratio of hard segment to softsegment of 2.5-4.0.

[0066] The polyether esters of this invention are useful in makingfibers, films and other shaped articles.

[0067] The fibers include monocomponent and multicomponent fiber such asbicomponent fiber (containing the polyether ester as at least onecomponent), and can be continuous filaments or staple fiber. The fibersare used to prepare woven, knit and nonwoven fabric. The nonwovenfabrics can be prepared using conventional techniques such as use formeltblown, spunbonded and card and bond fabrics, including heat bonding(hot air and point bonding), air entanglement, etc.

[0068] The fibers are preferably at least about 10 denier (11 dtex), andpreferably are up to about 2,000 denier (2,200 dtex), more preferably upto about 1,200 denier (1,320 dtex), and most preferably up to about 120denier (132 dtex).

[0069] Spinning speeds can be at least about 200 meters/minute (m/min),more preferably at least about 400 m/min, and ever more preferably atleast about 500 m/min, and can be up to about 1,200 m/min or higher.

[0070] The fibers can be drawn from about 1.5× to about 6×, preferablyat least about 1.5× and preferably up to about 4×. Single step draw isthe preferred drawing technique. In most cases it is preferred not todraw the fibers.

[0071] The fibers can be heat set, and preferably the temperature is atleast about 140° C. and preferably up to about 160° C.

[0072] Finishes can be applied for spinning or subsequent processing,and include silicon oil, mineral oil, and other spin finishes used forpolyesters and polyether ester elastomers, etc.

[0073] The fibers are stretchy, have good chlorine resistance, can bedyed under normal polyester dyeing conditions, and have excellentphysical properties, including superior strength and stretch recoveryproperties, particularly improved unload power and stress decay.

[0074] Conventional additives can be incorporated into the polyetherester or fiber by known techniques. The additives include delusterants(e.g., TiO₂, zinc sulfide or zinc oxide), colorants (e.g., dyes),stabilizers (e.g., antioxidants, ultraviolet light stabilizers, heatstabilizers, etc.), fillers, flame retardants, pigments, antimicrobialagents, antistatic agents, optical brightners, extenders, processingaids, viscosity boosters, and other functional additives.

EXAMPLES

[0075] The following examples are presented to illustrate the inventionand are not intended to be limiting. Therein, all percentages, parts,etc., are by weight unless otherwise indicated.

Hard Segment Weight Percentage Calculation

[0076] The weight percent hard segment was calculated according to thefollowing formula:

100(M_(hs))[(w₁M₁)−(w₂/M₂)](M_(hs))[(w₁/M₁)−(w₂/M₂)]+(M_(ss))(w₂/M₂)

[0077] where:

[0078] w₁ is weight of the dicarboxylic acid equivalent

[0079] w₂ is weight of the glycol

[0080] M₁ is molecular weight of the dicarboxylic acid equivalent in amu

[0081] M₂ is molecular weight of the glycol in atomic mass units (“amu”)(grams/mole)

[0082] M_(hs) is molecular weight of the hard segment repeat unit in amu(grams/mole)

[0083] M_(ss) is molecular weight of the soft segment in amu(grams/mole)

Number Average Molecular Weight (Mn)

[0084] The number average molecular weights (Mn) of polytrimethyleneether glycols were determined either by analyzing hydroxyl end-groupsusing NMR spectroscopic method or by titration. Hydroxyl number wasdetermined according to ASTM E222 method and is the way that should beused to analyze whether something is within the scope of this invention.

Inherent Viscosity

[0085] Inherent Viscosity (IV) measurements were made following ASTMMethod 2857-70. The polymer samples were dried at 70° C. for 3 hoursbefore weighing. Samples were run at 30° C. using a 0.5% solution inm-cresol. To improve efficiency, accuracy, and precision an AutoVisc®Automatic Measuring System (Design Scientific, Gainesville, Ga., U.S.A.,now believed to be manufactured by Cannon Instruments, State College,Pa., U.S.A. under the name AutoVisc® I) automated viscosity measuringsystem was used. A high density infrared fiber optic detection systemwas used in place of a human operator and an air bath was used in placeof the oil or water bath normally used to provide constant temperature.The AutoVisc exceeds the accuracy specifications of ASTM D-445,“Standard Test Method For Kinematic Viscosity of Transparent and OpaqueLiquids”.

Fiber Spinning Procedure 1

[0086] To perform the melt spinning, a cylindrical cell of 2.2 cm (⅞inch) inside diameter and 12.7 cm (5 inch) length was employed. The cellwas equipped with a hydraulically driven ram that was inserted on top ofthe sample. The ram had a replaceable Teflon® tip designed to fit snuglyinside the cell. An annular electric heater which surrounded the lowerquarter of the cell was used for controlling cell temperature. Athermocouple inside the cell heater recorded the cell temperature.Attached to the bottom of the cell was a spinneret, the interior ofwhich included a cylindrical passage, measuring 1.27 cm (0.5 inch) indiameter and 0.64 cm (0.25 inch) in length, which was connected to thebottom of the cell cavity. The spinneret cavity contained stainlesssteel filters of the following mesh, inserted in the following order,starting from the bottom (i.e., closest to the exit): 50, 50, 325, 50,200, 50, 100, 50. A compressible annular aluminum seal was fitted to thetop of the “stack” of filters. Below the filters was a cylindricalpassage of about 2.5 cm (1 inch) length and 0.16 cm ({fraction (1/16)}inch) interior diameter, the lower of which was tapered (at an angle of60 degrees from the vertical) to meet with an outlet orifice measuring0.069 cm (0.027 inch) in length and 0.023 cm (0.009 inch) in insidediameter. The spinneret temperature was controlled by a separate annularheater. The exiting filament was wrapped around a set of feed rollsoperated at 40 meters/minute, followed by a set of draw rolls operatedat 160 meters/minute (4×draw ratio), and then delivered to the finalpackage. The ratio of the speed of the draw roll to the feed rolldefines the draw ratio. Physical properties reported herein are forfibers spun at a draw ratio of 4.

Fiber Spinning Procedure 2

[0087] The procedures of Fiber Testing Procedure 1 were run, except thatthe draw rolls operated at 80 meters/minute (draw ratio 2×).

Fiber Tenacity and Elongation

[0088] Tenacity at break, T, in grams per denier (gpd) and percentelongation at break, E, were measured on an Instron® Tester equippedwith a Series 2712 (002) Pneumatic Action Grips equipped with acryliccontact faces. The test was repeated three times and then the average ofthe results is reported.

[0089] The average denier for the fibers used in the tenacity andelongation measurements is reported as Den 1.

Fiber Unload Power, Stress Decay and Percent Set

[0090] The average denier for the fibers used in measuring unload power,stress decay and percent set is reported as Den 2.

[0091] Unload power was measured in dN/tex_(eff)×1000. One filament, a2-inch (5 cm) gauge length, was used for each determination. Separatemeasurements were made using zero-to-300% elongation cycles. Unloadpower (i.e., the stress at a particular elongation) was measured afterthe samples have been cycled five times at a constant elongation rate of1000% per minute and then held at 300% extension for half a minute afterthe fifth extension. While unloading from this last extension, thestress, or unload power, was measured at various elongations. Unloadpowers are reported herein as the effective unload power using thegeneral form “UP x/y” where x is the percent elongation to which thefiber was cycled five times and y is the percent elongation at which thestress, or unload power, was measured.

[0092] Stress Decay was measured as the percent loss of stress on afiber over a 30 second period with the sample held at 300% extension atthe end of the fifth load cycle.

S=((F−C)*100)/F

[0093] where:

[0094] S=Stress Decay, %

[0095] F=Stress at full extension

[0096] C=Stress after 30 seconds

[0097] The percent set was measured from the stress/strain curverecorded on chart paper.

Abbreviations

[0098] For convenience, several abbreviations are employed herein: 3GTPolytrimethylene terephthalate 3GT hard segment Polytrimethyleneterephthalate hard segment formed from 1,3-propanediol and dimethylterephthalate (DMT) PO4G Polytetramethylene ether glycol PO4G softsegment Polytetramethylene ether glycol soft segment formed frompolytetramethylene ether glycol and DMT THF/3MeTHF Copolymer oftetrahydrofuran and 3- methyl tetrahydrofuran THF/3MeTHF soft Softsegment from THF/3MeTHF segment PO3G Polytrimethylene ether glycol PO3Gsoft segment Soft segment from polytrimethylene ether glycol and DMTPO3G/3GT An elastomer comprising PO3G soft Elastomer segment and 3GThard segment PO4G/3GT An elastomer comprising PO4G soft Elastomersegment and 3GT hard segment THF/3MeTHF/3GT An elastomer comprisingTHF/3MeTHF elastomer soft segment and 3GT hard segment

PO3G Preparation

[0099] PO3G having a number average molecular weight of 2360 wasprepared in accordance with Example 4 of pending U.S. patentapplication, Ser. No. 09/738,688, filed Dec. 15, 2000 (corresponding toWO 01/44348).

[0100] PO3G having a number average molecular weight of 3080 wasprepared following the procedure described above in a 2 L reactorvessel. The polymerization was carried out for 36 hours at 160-170° C.and the hydrolysis of the polymer was conducted at 100° C. for 6 hours.

Elastomer Preparation

[0101] To prepare the elastomers a two-piece resin kettle was used. The80 mm diameter, 500 mL capacity kettle bottom was connected to athree-neck kettle top with an o-ring and clamp. One joint was fit with atake-off arm leading to a cold trap to condense volatile reactionby-products. The cold trap in turn was connected to a manifold capableof delivering an inert gas such as argon or nitrogen or providing avacuum. The reaction was stirred using a mechanical agitator fitted witha stainless-steel paddle stirrer and was interfaced with a Cole-ParmerServodyne® Controller 4445-30 torquemeter. The torquemeter allowed eachrun to be reproducibly terminated at a predefined torque reading.

Example 1

[0102] A resin kettle was charged with 50.0 g (21.3 mmol) of PO3Gpolyether glycol having a number average molecular weight of 2360, 16.3g (214 mmol) of 1,3-propanediol, 19.0 g (97.8 mmol) dimethylterephthalate, and 0.3 g Ethanox® 330 antioxidant. The flask wasevacuated and backfilled with N2 gas three times to create an inertatmosphere. Under a positive N₂ gas flow 1.0 mL of catalyst solution wasadded. The catalyst was Tyzor® TBT Tetrabutyl Titanate (available fromE.I. du Pont de Nemours and Company, Wilmington, Del.) and was used as a5% solution in 1,3-propanediol. The reaction was heated by immersion ina Tin/Bismuth metal bath. The polymerization was allowed to proceed for45 minutes at 240° C. under N₂. At that point vacuum was introduced, andthe pressure was lowered from atmospheric to 0.05-0.10 mm Hg (6.7 to13.3 Pa) over 90 min. The reaction was continued under vacuum at 240° C.until sufficient viscosity was achieved. The flask was backfilled withN₂ and the polymer was removed while still hot. Isolated yieldstypically ranged from 70-90%. Fibers were prepared according to FiberSpinning Procedure 1. Properties are provided in Table 1.

Comparative Example A

[0103] Example 1 was repeated however, PO4G, polytetramethylene etherglycol, molecular weight of 2000, was used in place of the PO3G.Properties are provided in Table 1.

Comparative Example B

[0104] Example 1 was repeated however, a copolymer of tetrahydrofuranand 3-methyltetrahydrofuran (92% THF/8% 3MeTHF), with molecular weightof 2117, was used in place of the PO3G. Properties are provided in Table1.

Example 2

[0105] Example 1 was repeated using a Spinning procedure 2 (2×draw ratioinstead of 4×draw ratio). Properties are provided in Table 1.

Comparative Example C

[0106] Example 2 was repeated however, PO4G, polytetramethylene etherglycol, molecular weight of 2000, was used in place of the PO3G.Properties are provided in Table 1.

Comparative Example D

[0107] Example 2 was repeated however, a copolymer of tetrahydrofuranand 3-methyltetrahydrofuran (92% THF/8% 3MeTHF), with molecular weightof 2117, was used in place of the PO3G. Properties are provided inTable 1. TABLE 1 HS/SS Tenacity Elong- Stress % Mole Draw Den (grams/ation Den Unload Decay Set Ex. SS HS HS Ratio IV Ratio 1 denier) (%) 2Power (%) (%) 1 PO3G 3GT 23.0 3.59 1.58 4X 87 0.56 425 78 121 13.24 41 APO4G 3GT 23.0 3.15 1.72 4X 120 0.54 430 119 55 26.57 33 B THF/ 3GT 22.83.22 1.73 4X 89 0.63 372 93 88 25.15 28 3Me- THF 2 PO3G 3GT 23.0 3.591.58 2X 74 0.38 591 79 82 12.2  50 C PO4G 3GT 23.0 3.15 1.72 2X 80 0.44532 77 54 22.00 42 D THF/ 3GT 22.8 3.22 1.73 2X 74 0.42 443 68 94 19.5626.1 3Me- THF

[0108] As can be seen from Table 1, the polyether ester elastomersderived from soft segments of polytrimethylene ether glycol provideimproved properties in terms of stretch-recovery (unload power, % setand stress decay) in comparison with polyether esters known in the art,particularly higher unload power and less stress decay.

[0109] The higher unload power shows that less material is necessary toachieve a desired retractive force. The lower stress decay shows thatelastic garments made with the fibers of the invention will retain theirelasticity over repeated or extended use.

Examples 3

[0110] Example 1 was repeated using polytrimethylene ether glycol havinga Mn of 3080 and by varying the amounts of the reactants. Properties areprovided in Table 2.

Example 4

[0111] Example 3 was repeated using a Spinning Procedure 2 (2×draw ratioinstead of 4×draw ratio). Properties are provided in Table 2. TABLE 2HS/SS Tenacity Elong- Stress % Mole PO3G Draw Den (grams/ ation DenUnload Decay Set Ex. HS Ratio Mn IV Ratio 1 denier) (%) 2 Power (%) (%)3 17 3.19 3080 1.55 4X 70 0.44 434 87 83 11.15 29 4 17 3.19 3080 1.55 2X68 0.27 642 58 69 11.08 32

[0112] The foregoing disclosure of embodiments of the present inventionhas been presented for purposes of illustration and description. It isnot intended to be exhaustive or to limit the invention to the preciseforms disclosed. Many variations and modifications of the embodimentsdescribed herein will be obvious to one of ordinary skill in the art inlight of the above disclosure. The scope of the invention is to bedefined only by the claims appended hereto, and by their equivalents.

What is claimed is:
 1. A polyether ester elastomer comprising about90—about 60 weight % polytrimethylene ether ester soft segment and about10—about 40 weight % trimethylene ester hard segment.
 2. A polyetherester as claimed in claim 1 about 85—about 70 weight % polytrimethyleneether ester soft segment and about 15—about 30 weight % trimethyleneester hard segment.
 3. A polyether ester as claimed in claim 1 about82—about 74 weight % polytrimethylene ether ester soft segment and about18—about 26 weight % trimethylene ester hard segment.
 4. A polyetherester as claimed in claim 1 wherein the mole ratio of hard segment tosoft segment is in the range of about 2.0-about 4.5.
 5. A polyetherester as claimed in claim 1 wherein the mole ratio of hard segment tosoft segment is in the range of about 2.5-about 4.0.
 6. A polyetherester as claimed in claim 1 having an inherent viscosity of about1.4-about 2.4 dl/g.
 7. A polyether ester as claimed in claim 1 preparedby providing and reacting (a) polytrimethylene ether glycol, (b)1,3-propanediol and (c) dicarboxylic acid, ester, acid chloride or acidanhydride.
 8. A polyether ester as claimed in claim 7 wherein thepolytrimethylene ether ester soft segment is prepared from polymericether glycol and the dicarboxylic acid, ester, acid chloride or acidanhydride, greater than 50 weight % of the polymeric ether glycol usedto form the polytrimethylene ether ester soft segment is thepolytrimethylene ether glycol.
 9. A polyether ester as claimed in claim7 wherein the polytrimethylene ether ester soft segment is prepared frompolymeric ether glycol and the dicarboxylic acid, ester, acid chlorideor acid anhydride, at least 40 weight % of the polymeric ether glycolused to form the polytrimethylene ether ester soft segment is thepolytrimethylene ether glycol, and up to 60 weight % of the polymericether glycol used to form the polytrimethylene ether ester soft segmentis polymeric ether glycol selected from the group consisting ofpolyethylene ether glycol, polypropylene ether glycol,polytetramethylene ether glycol, polyhexamethylene ether glycol, andcopolymers of tetrahydrofuran and 3-alkyl tetrahydrofuran, and mixturesthereof.
 10. A polyether ester as claimed in claim 9 wherein at least 85weight % of the polymeric ether glycol used to form the polytrimethyleneether ester soft segment is the polytrimethylene ether glycol.
 11. Apolyether ester as claimed in claim 7 wherein the polytrimethylene etherglycol has number average molecular weight of at least about 1,000. 12.A polyether ester as claimed in claim 7 wherein the polytrimethyleneether glycol has number average molecular weight of about 1,000-about5,000.
 13. A polyether ester as claimed in claim 7 wherein thepolytrimethylene ether glycol has number average molecular weight ofless than about 5,000.
 14. A polyether ester as claimed in claim 7wherein the polytrimethylene ether glycol has a number average molecularweight in the range of about 1,500 to about 3,500.
 15. A polyether esteras claimed in claim 7 wherein the trimethylene ester hard segment isprepared from diol and the dicarboxylic acid, ester, acid chloride oracid anhydride, at least 75 mole % of the diol used to form thetrimethylene ester hard segment is 1,3-propanediol and up to 25 mole %of the diol is diol other than 1,3-propanediol with 2-15 carbon atoms.16. A polyether ester as claimed in claim 15 wherein the diol other than1,3-propanediol are selected from ethylene, isobutylene, tetramethylene,pentamethylene, 2,2-dimethyltrimethylene, 2-methyltrimethylene,hexamethylene and decamethylene glycols, dihydroxy cyclohexane,cyclohexane dimethanol, hydroquinone bis(2-hydroxyethyl) ether, andmixtures thereof.
 17. A polyether ester as claimed in claim 15 whereinthe diol other than 1,3-propanediol contain 2-8 carbon atoms.
 18. Apolyether ester as claimed in claim 15 wherein the diol other than1,3-propanediol are selected from the group consisting of ethyleneglycol and 1,4-butanediol, and mixtures thereof.
 19. A polyether esteras claimed in claim 15 wherein at least 85 mole % of the diol used toform the trimethylene ester hard segment is 1,3-propanediol.
 20. Apolyether ester as claimed in claim 7 wherein the dicarboxylic acid,ester, acid chloride or acid anhydride is an aromatic dicarboxylic acidor diester.
 21. A polyether ester as claimed in claim 7 wherein thedicarboxylic acid, ester, acid chloride or acid anhydride is selectedfrom the group consisting of dimethyl terephthalate, bibenzoate,isophthlate, phthalate and naphthalate; terephthalic, bibenzoic,isophthalic, phthalic and naphthalic acid, and mixtures thereof.
 22. Apolyether ester as claimed in claim 7 wherein at least 50 mole % thedicarboxylic acid, ester, acid chloride or acid anhydride is selectedfrom the group consisting of terephthalic acid and dimethylterephthalate.
 23. A polyether ester as claimed in claim 7 wherein thedicarboxylic acid, ester, acid chloride or acid anhydride is selectedfrom the group consisting of terephthalic acid and dimethylterephthalate.
 24. A polyether ester as claimed in claim 7 having aninherent viscosity of about 1.4-about 2.4 dl/g, wherein the mole ratioof hard segment to soft segment is in the range of about 2.0-about 4.5;the polytrimethylene ether ester soft segment is prepared from polymericether glycol and the dicarboxylic acid, ester, acid chloride or acidanhydride; at least 40 weight % of the polymeric ether glycol used toform the polytrimethylene ether ester soft segment is thepolytrimethylene ether glycol having a number average molecular weightof about 1,000-about 5,000, up to 60 weight % of the polymeric etherglycol used to form the polytrimethylene ether ester soft segment ispolymeric ether glycol selected from the group consisting ofpolyethylene ether glycol, polypropylene ether glycol,polytetramethylene ether glycol, polyhexamethylene ether glycol, andcopolymers of tetrahydrofuran and 3-alkyl tetrahydrofuran, and mixturesthereof; the trimethylene ester hard segment is prepared from diol andthe dicarboxylic acid, ester, acid chloride or acid anhydride; at least75 mole % of the diol used to form the trimethylene ester hard segmentis 1,3-propanediol and up to 25 mole % of the diol are diol selectedfrom ethylene, isobutylene, tetramethylene, pentamethylene,2,2-dimethyltrimethylene, 2-methyltrimethylene, hexamethylene anddecamethylene glycols, dihydroxy cyclohexane, cyclohexane dimethanol,hydroquinone bis(2-hydroxyethyl) ether, and mixtures thereof; and thedicarboxylic acid, ester, acid chloride or acid anhydride is selectedfrom the group consisting of dimethyl terephthalate, bibenzoate,isophthlate, phthalate and naphthalate, terephthalic, bibenzoic,isophthalic, phthalic and naphthalic acid, and mixtures thereof.
 25. Apolyether ester as claimed in claim 7 having an inherent viscosity ofabout 1.4-about 2.4 dl/g, wherein the mole ratio of hard segment to softsegment is in the range of about 2.5-about 4.0, at least 85 weight % ofthe polymeric ether glycol used to form the polytrimethylene ether estersoft segment is the polytrimethylene ether glycol; at least 85 mole % ofthe diol used to form the trimethylene ester hard segment is the1,3-propanediol; the polytrimethylene ether glycol has a number averagemolecular weight in the range of about 1,500 to about 3,500; at least 70mole % the dicarboxylic acid, ester, acid chloride or acid anhydride isselected from the group consisting of terephthalic acid and dimethylterephthalate.
 26. A polyether ester as claimed in claim 1 prepared byproviding and reacting polytrimethylene ether glycol andpolytrimethylene ester.
 27. A polyether ester comprising a soft segmentrepresented by the structure:

and a hard segment represented by the structure:

 where x is about 17 to about 86 and R and R′, which may be the same ordifferent, are divalent radicals remaining after removal of carboxylfunctionalities from dicarboxylic acid equivalent.
 28. A polyether esteras claimed in claim 1 in the form of a fiber.
 29. A polyether ester asclaimed in claim 28 wherein the fiber is a monocomponent filament.
 30. Apolyether ester as claimed in claim 28 wherein the fiber is a staplefiber.
 31. A polyether ester as claimed in claim 1 wherein the polyetherester in the form of a component of a multicomponent fiber.
 32. A wovenor knit fabric comprising fibers comprising the polyether ester ofclaim
 1. 33. A nonwoven fabric comprising fibers comprising thepolyether ester of claim
 1. 34. A process of preparing a polyether esteras claimed in claim 1 by providing and reacting (a) polytrimethyleneether glycol, (b) 1,3-propanediol and (c) dicarboxylic acid, ester, acidchloride or acid anhydride.
 35. A process of preparing a polyether esteras claimed in claim 1 by providing and reacting polytrimethylene etherglycol and trimethylene ester.
 36. A process of preparing a polyetherester as claimed in claim 1 prepared by providing and reactingpolytrimethylene ether glycol and polytrimethylene ester.
 37. A processof preparing a fiber by providing the polyether ester of claim 1 andspinning the polyether ester to form a fiber.
 38. A process of preparinga fabric comprising (a) providing fibers, the fibers comprising fiberscomprising the polyether ester of claim 1 and (b) forming a fabric fromthe fibers.